Solid state Physics I Lecture 1
Dr. Abdelrahman Lashin
Assoc. Prof. Physics Department
Course Information: Instuctor
• Instructor: Associate Prof. Dr. Abdelrahman Lashin
• Office: 239 -1st flour
• Office hours: 10:00-12:00 am Sunday., Tuesday
• Telephone: 0561173457
• Email: [email protected]
Course Information: Materials
Course Information: Grading
• Final Exam (50%)
• Attendance Lecture/Recitation Quiz (7%)
• Homework (6%)
• Scientific Report (7)
• 1st Mid-term Exam (15%)
• 2nd Mid-term Exam (15%)
Crystallography
Crystallography ≡
The branch of science that deals with the geometric description of crystals & their internal arrangements.It is the science of crystals & the math. used to describe them.
The purpose of Ch. 1 of Kittel’s book is mainly to introduce this terminology to you.
Crystal Lattice
•A Crystal Lattice (or a Crystal) ≡ A 3-dimensional periodic array of atoms. we imagine each atom replaced by a mathematical point at the equilibrium position of that atom.
•Ideal Crystals. “Ideal” means one with no defects. That is, no missing atoms, no atoms off of the lattice sites, no impurities. The ideal crystal never occurs in nature.
Platinum
Platinum Surface
(Scanning Tunneling Microscope)
Crystal Lattice
Structure of Platinum
• The simplest structural unit for a given solid is called the BASIS
• The simplest structural unit we can imagine is a Single Atom.
This corresponds to a solid made up of only one kind of atom ≡ An Elemental Solid.
• However, this structural unit could also be a
group of several atoms or even molecules.
Lattice
Crystal Structure
Crystalline Periodicity
Crystal Structure ≡ Lattice + Basis
A two-dimension example, see the figure.
Basis
Crystal Structure ≡ Lattice + Basis
A three- demension example, see the figure.
Crystalline Periodicity
Lattice
Basis
Crystal Structure
Crystal Lattices
Bravais Lattices (BL)
All atoms are the same kind All lattice points are equivalent
Non-Bravais Lattices (non-BL)
Atoms are of different kinds. Some lattice points are not equivalent.
